Article 3d: Emotion Modulation in PTSD: Clinical and Neurobiological Evidence for a Dissociative Subtype (Lanius et al., 2010)

Question 1

2 types of PTSD

Answer 1

1. Dissociative type: emotional overmodulation –> too much prefrontal inhibition in the limbic regions.
2. Re-experiencing and hyperarousal type: emotional undermodulation –> failure of prefrontal inhibition in limbic regions.

Question 2

Peri-traumatic dissociation

Answer 2

Dissociation at the moment of (or right after) the traumatic event. Can include alterations of:
- Time sense
- Perception
- Attentional focus
- Awareness of pain
- Depersonalisation
- Compartmentalisation

Question 3

Compartmentalisation

Answer 3

Information related to the traumatic event is often differently encoded in a dissociative state, resulting in a decreased access to information about the trauma after the event. This gives a sense of cognitive fragmentation or emotional detachment from the experience. The cost of this detachment may be avoidance of necessary cognitive and affective processing of the trauma in it’s aftermath.

Question 4

The consequences of acute dissociative responses

Answer 4

This predicts the development of chronic PTSD, because it often results in a chronic pattern of dissociation when being exposed to reminders of the trauma.

Question 5

Research paradigm

Answer 5

Patients were asked to relive their trauma in a brain scanner, and neurobiological patterns were studied during this.

Question 6

Results

Answer 6

Psychological responses to recalling trauma can differ significantly between people with chronic PTSD:
- 70% showed a re-experiencing rate with increased heart-rate.
- 30% showed an opposite brain activation patter, with a dissociative response and without an increased heart-rate.

Question 7

Undermodulation of affect/ emotional undermodulation

Answer 7

Caused by failure of cortico-limbic inhibition.
People with re-experiencing/hyperarousal PTSD exhibit abnormally low activation in the medial anterior brain regions, which causes failure of the cortico-limbic inhibition and increases activation of the limbic system (heart rate etc.)

Question 8

Overmodulation of affect/ emotional overmodulation

Answer 8

Caused by excessive cortico-limbic inhibition.
People with dissociative PTSD exhibit abnormally high activation in brain regions that are involved in arousal modulation. This causes excessive inhibition of the limbic regions, which can cause dissociations, depersonalisation, derealisation etc.

Question 9

Dissociative PTSD

Answer 9

Often due to early onset of traumatic experiences and chronic trauma.

Question 10

Treatment

Answer 10

In re-experiencing PTSD, exposure can be helpful to decrease physiological responses to traumatic memories. But in people with dissociative PTSD, this can increase the PTSD symptoms if the dissociative response isn’t reduced first!